System and method for quantifying the presence of components in the exhaust of commercial and/or heavy-duty vehicles

ABSTRACT

A system and/or method for quantifying the presence of one or more components in vehicle exhaust, and more particularly to a non-contact, sampling system and method for quantifying the presence of one or more components in exhaust emissions of commercial and/or heavy-duty vehicles that emit exhaust at an elevated level, under actual operating conditions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application is a continuation-in-part of U.S. patent applicationSer. No. 13/052,815, filed Mar. 21, 2011 now U.S. Pat. No. 8,266,952,which is a continuation of U.S. patent application Ser. No. 12/114,189,filed May 2, 2008 (which issued as U.S. Pat. No. 7,930,931 on Apr. 26,2011), each of which are hereby incorporated by reference herein intheir entirety.

FIELD OF THE INVENTION

The invention relates generally to the quantification of the presence ofone or more components in vehicle exhaust, and more particularly to anon-contact, extractive sampling system and method for quantifying thepresence of one or more components in exhaust emissions of commercialand/or heavy-duty vehicles that emit exhaust at an elevated level, underactual operating conditions.

BACKGROUND OF THE INVENTION

Systems and methods for monitoring the exhaust gas composition and fineparticle composition of exhaust emissions of various types of vehiclesare known. For example, with regard to automobiles, it is common foremissions inspection stations (or automotive repair facilities) toutilize dynamometers for controlled engine loading tests for thepurposes of exhaust emission measurement. One drawback associated withdynamometer testing, however, is that the measurements acquired often donot represent emissions under actual operating conditions whenautomobiles are in motion on a roadway or other driving surface.

To remedy these and other drawbacks associated with dynamometer testing,remote emissions sensing systems have been developed to remotely monitorthe exhaust gas composition of automobiles traveling past “test sites”located along streets or highways. Examples of remote emissions sensing(or “cross-road”) systems are described in, for example, U.S. Pat. Nos.5,210,702, 5,319,199, 5,401,967, 5,591,975, 5,726,450, 5,797,682,5,831,267, and 5,877,862, each of which is hereby incorporated herein byreference in its entirety.

However, existing systems configured to remotely test emissions tend tofocus on passenger cars with exhaust systems that emit exhaustrelatively close to the ground. By contrast, many commercial and/orheavy-duty vehicles, such as tractor-trailers, buses, commercial trucks,and/or other vehicles, have exhaust systems that emit exhaust at a point(or points) relatively high above the ground. For example, commercialdiesel vehicles may include exhaust stacks that extend up verticallyfrom the vehicles and emit exhaust up into the air.

As should be appreciated, exhaust leaving the exhaust pipe(s) of amoving commercial and/or heavy-duty vehicle (e.g., via exhaust “stacks”of a semi-tractor) is entrained in the vehicle's turbulent wake andcontinues to dissipate as the vehicle travels away. Despite the presentturbulence, the dissipation of the exhaust will have a directionalityassociated with one or both of the location at which the exhaust isemitted and/or the direction in which it is propelled by momentum uponbeing emitted. For example, commercial and/or heavy-duty vehiclesgenerally emit exhaust at an elevated position and/or propel emittedexhaust either upwards or to the side. As a result, remote emissionssensing systems designed to detect emissions for low-emitting vehicles(e.g., typical passenger automobiles) may not accurately quantify thepresence of components in the exhaust of commercial and/or otherheavy-duty vehicles.

Conventional remote sensing systems may further produce results that maynot be indicative of the emissions of a commercial or heavy-duty vehiclebecause, depending on the placement of the remote sensing system and/orthe operation of the commercial or heavy-duty vehicle, emissions fromthe vehicle may be measured while the vehicle is being operated in anatypical manner. For example, the emissions may be measured while thevehicle is changing gears. Measurements taken during a brief period ofatypical operation may inaccurately indicate elevated levels of emissionby the vehicle.

These and other problems can reduce the benefits of remote emissionssensing systems.

SUMMARY OF THE INVENTION

The invention addressing these and other drawbacks in the art relatesgenerally to the quantification of the presence of one or morecomponents in vehicle exhaust, and more particularly to a non-contact,extractive sampling system and method for quantifying the presence ofone or more components in exhaust emissions of commercial and/orheavy-duty vehicles that emit exhaust at an elevated level (e.g., from astack exhaust system), under actual operating conditions.

According to various implementations of the invention, to quantify thepresence of one or more components in exhaust emissions of a commercialand/or heavy-duty vehicle that emits exhaust at an elevated level, agathering structure and collector (or extraction tube) may be positioneddirectly over and/or adjacent to a path of the vehicle such that thegathering structure directs exhaust emitted by the vehicle at anelevated level above the roadway to the collector. The collector mayreceive at least a portion of the exhaust directed thereto by thegathering structure into one or more openings (or extraction holes)formed in the collector. A flow generator in fluid communication withthe collector may generate a flow of air that draws exhaust directed tothe collector by the gathering structure into the one or more openingsof the collector. The flow of air generated by the flow generator maydeliver the exhaust received into the one or more openings to acomponent detection system. Generally, the component detection systemmay quantify the presence in the exhaust of major gaseous exhaustspecies (e.g., concentrations of CO₂ or H₂O), along with the presence ofone or more minor exhaust gases (e.g., carbon monoxide (CO),hycrocarbons (HC), oxides of nitrogen (NO_(x)), etc.), and/or fineparticulate matter present in the exhaust (e.g., quantified as smoke,opacity, particle mass, particle scatter, etc.) so that emission indicesfor the minor exhaust gases and/or fine particulate matter thatrepresent the amount of pollutants in the exhaust above backgroundlevels may be deduced.

In certain implementations, the gathering structure may be disposed ator near the roadway, and may have at least one surface that causesexhaust emitted by the vehicle at an elevated level (e.g., from a stackexhaust system) to gather around the collector. The roadway may be anactual road lane, and/or may be a separate test lane. In someimplementations, the gathering structure may include a roof that spansthe path of the vehicle in the roadway, and the collector may bedisposed such that the collector openings are located at or near anunderside surface of the roof. In such implementations, exhaust ejectedby the vehicle may be gathered and pooled around the collector openingsby the underside surface of the roof, which may facilitate the receptionof the exhaust into the collector openings. In some instances, thegathering structure may be impermeable to one or both of .water and/orexhaust gases. In these instances, the gathering structure may furtherprovide shelter for the collector openings and/or emitted exhaust fromprecipitation. Since the introduction of precipitation into thecollector openings may interfere with the operation of the collector,the component detection system, and/or the flow generator generating theflow of air from the collector openings to the component detectionsystem, the provision of shelter by the gathering structure may furtherenhance the collection and analysis of exhaust emitted by the vehicle atan elevated level.

According to various implementations, the gathering structure mayinclude a tent-like structure. The roof of the gathering structure maybe formed to guide exhaust that is emitted in a generally verticaldirection toward the collector. For example, the roof of the gatheringstructure may be an “A-frame” root with the collector running along theunderside of the roof at the interface between the two slopes of the“A-frame.” The collector may be formed from a perforated pipe that runsalong the underside of the roof at a position to which exhaust emittedin a substantially vertical direction is guided by the gatheringstructure.

In some implementations, the collector having one or more collectoropenings may be disposed along the path of the vehicle such that exhaustemitted by the vehicle at an elevated level (e.g., from a stack exhaustsystem) may be received into the one or more collector openings. Thecollector may include a conduit that communicates the received exhaustfrom the one or more collector openings to the component detectionsystem that quantifies the presence of one or more components in thereceived exhaust.

In some implementations, the collector includes a plurality of collectoropenings that are arranged above the surface of a roadway along whichthe vehicle is traveling so as to receive the emissions of the vehicle,which are emitted at an elevated level (e.g., from high-stacks). Forexample, the collector may include a perforated pipe that forms theopenings. In certain implementations, the collector may be disposed suchthat the collector openings are arranged along a path from between afirst location and a second location that corresponds to the path of thevehicle between the first location and the second location. For example,the collector openings may be disposed in an array above the path of thevehicle between the first location and the second location to receiveexhaust emitted upwards by the vehicle. This may facilitate thecollection of exhaust by the collector openings, as exhaust emitted fromthe vehicle will be directed by momentum, turbulence, and/or otherphenomena to the collector openings as the vehicle travels along theroadway.

According to some implementations, the flow generator may be configuredto generate a flow of air that enables a continuous or periodic samplingof the air received into the collector openings at a predetermined flowrate. As the vehicle passes by the collector openings and exhaust fromthe vehicle is drawn into the collector openings toward the componentdetection system, the pressure in the conduit formed by the collectormay decrease from atmospheric pressure at or near the collectoropenings, to a predetermined pressure level at a measurement space orcell associated with the component detection system where the presenceof one or more components within the exhaust are quantified.

Characteristics of the collector and/or the collector openings (e.g.,arrangement of the openings, length, diameter, cross-section, etc.),and/or operating parameters of the flow generator may be adjusted asnecessary to achieve desired flow rates and pressure drops within thecollector. Such adjustments to these and other components of the systemmay ensure that optimal conditions exist for quantifying the presence ofone or more components in an exhaust sample delivered to the componentdetection system. Optimal conditions may vary depending on, for example,which molecular species of interest are being measured, as well as whichtype of component detection system is being implemented.

In various implementations, the collector may be configured such thatcollection times for exhaust emissions emitted by the vehicle to beconveyed through the collector to the component detection system vary asa function of position along the roadway. Collection times may be longerfor locations that are closer to the first location, and shorter forlocations that are closer to the second location. Since exhaustemissions are emitted first at the first location and then on toward thesection location (e.g., as the vehicle proceeds along the roadway), thedifferences in collection times may cause exhaust emissions collectedalong the roadway to be aggregated into a condensed body of exhaust thatis conveyed by the collector to the component detection system. Toprovide collection times that will result in exhaust emissionaggregation, the size and/or shape of collector openings, the sizeand/or shape of lumen cross-section, lumen length, flow generatorparameters, and/or other factors may be adjusted or configured. One ormore of these factors may be controlled dynamically (e.g., based onvehicle speed) to ensure aggregation of the exhaust emissions.Aggregation of the exhaust emissions may increase the concentrations ofthe exhaust emissions, which may enhance the precision and/or accuracyof the analysis performed by the component detection systems.

According to an implementation of the invention, the component detectionsystem may comprise any system capable of quantifying the presence ofone or more components in exhaust. For instance, the component detectionsystem may include a trace gas detection system comprising one or moreof a mass spectrometer, visible/ultraviolet absorption spectrometer,infrared absorption spectrometer, and/or other component detectioninstruments or systems. In some instances, the component detectionsystem may include a fine particle measurement system comprising one ormore of an aerosol mass spectrometer, condensation particle counter,light scattering detector, laser incandescent particle detector,electrostatic particle charging detector, and/or other fine particleinstruments or systems.

The system and method of the invention as disclosed herein may beutilized to quantify the presence of one or more components in aplurality of samples of exhaust taken according to a predeterminedsampling rate. In some instances, the quantification of the one or morecomponents in the exhaust for the plurality of samples may be aggregatedin order to provide an aggregated quantification of the one or morecomponents in the exhaust emitted by the vehicle. The aggregatedquantification may provide an enhanced accuracy and/or precision indetermining the quantity and/or nature of the emissions of the vehicle.For example, even if the vehicle is being operated in some atypicalfashion (e.g., changing gears) along the pathway, the aggregation of thequantification may suppress inaccuracies caused by this momentaryatypical operation. In some instances, the aggregated quantification maybe determined by averaging the quantifications of the presence of theone or more components in the plurality of exhaust samples.

According to one or more implementations, for a given test period (e.g.,a pass of the vehicle past the collector openings and/or the gatheringstructure), a computer (or processor) may correlate a record (or datafile) of quantification of the one or more components in the exhaust ofthe vehicle with a record of an identity, or other information,associated with the vehicle (e.g., registration information, etc.).

Both the record and vehicle identification/information may be stored ina memory associated with, or accessible by, the computer. Data regardingthe identification of those vehicles passing by the collector openingsand/or the gathering structure may be acquired by an imaging unit orother known identification device or system in operative communicationwith the computer (e.g., via a wireless or hard-wired connection). Othervehicle identification systems may be implemented.

Various other objects, features, and advantages of the invention will beapparent through the detailed description of the invention and thedrawings attached hereto. It is also to be understood that both theforegoing general description and the following detailed description areexemplary and not restrictive of the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a system for analyzing an exhaust plume of a vehicletraveling on a roadway, according to one or more implementations of theinvention.

FIG. 2 illustrates a system for analyzing an exhaust plume of a vehicletraveling on a roadway, according to one or more implementations of theinvention.

FIG. 3 illustrates a method of quantifying the presence of one or morecomponents in an exhaust plume of a vehicle traveling on a roadway, inaccordance with one or more implementations of the invention.

FIG. 4 illustrates a method of analyzing exhaust to quantify thepresence of one or more components in the exhaust, according to one ormore implementations of the invention.

FIG. 5 illustrates a system for analyzing an exhaust plume of a vehicletraveling on a roadway, according to one or more implementations of theinvention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a system 10 for analyzing an exhaust plume 12 of avehicle 14 traveling on a roadway 16 under actual operating conditions,in accordance with one or more implementations of the invention. Itshould be appreciated that exhaust leaving the exhaust pipe(s) of movingvehicle 14 (e.g., via exhaust “stacks” of a semi-trailer or bus) isentrained in the vehicle's turbulent wake and continues to dissipate asvehicle 14 travels away. Despite the present turbulence, the dissipationof the exhaust will have a directionality associated with one or both ofthe location at which the exhaust is emitted and/or the direction inwhich it is propelled by momentum upon being emitted. For example,commercial and/or heavy-duty vehicles generally emit exhaust at anelevated position and/or propel emitted exhaust either upwards or to theside. As a result, remote emissions sensing systems designed to detectemissions for low-emitting vehicles (e.g., typical passengerautomobiles) may not accurately quantify the presence of components inthe exhaust of commercial and/or other heavy-duty vehicles.

Roadway 16 may comprise any driving surface suitable for safe passage ofvehicle 14, and may further comprise a single vehicle travel lane, ormultiple vehicle travel lanes. Roadway 16 may comprise a road alongwhich vehicle 14 is traveling to its destination, or roadway 16 maycomprise a separate test lane (or lanes) to which vehicle 14 hasdetoured from its route in order to have its emissions tested separatefrom other traffic. System 10 may be particularly suited to analyzeexhaust where vehicle 14 is a semi-trailer truck, dump truck, tractor,bus, etc. that emits gas at an elevated level (in comparison with lowemitting passenger vehicles), such as through a stack exhaust emissionsystem.

In some implementations, system 10 may include one or more of acollector 18 (or extraction tube) , a gathering structure 20, a flowgenerator 22, a component detection system 24, a computer 26, a vehiclecommunication system 28, a position tracking system 30, a vehicleidentification system 32, and/or other components. As will be discussedfurther below, exhaust from exhaust plume 16 may be gathered bygathering structure 20 around collector 18, and pulled or extractedthrough collector 18, via suction generated by flow generator 22, tocomponent detection system 24 where the presence of one or morecomponents within the exhaust may be quantified. Upon analysis of theair provided to component detection system 24 through collector 18, theanalyzed air may be exhausted from system 10 via an exit pipe.

According to various implementations, gathering structure 20 may haveone or more surfaces that cause exhaust emitted by vehicle 14 to gatheraround one or more collector openings 36 (or extraction holes) formed incollector 18. Collector 18 may be disposed at or near such surfaces ofgathering structure 20. This may facilitate the reception of exhaustinto collector openings 36, as the exhaust gathered by gatheringstructure 20 remains concentrated around collector openings 36 for arelatively prolonged period of time, during which the gathered exhaustmay be drawn into collector 18 via collector openings 36. In someinstances, collector 18 may include a conduit, or conduits, formedintegrally with gathering structure 20. In such instances, collectoropenings 36 may be formed as openings in a surface of gatheringstructure 20 that communicate with the conduit, or conduits, formedintegrally with gathering structure 20.

In some implementations the one or more surfaces of gathering structure20 that cause exhaust emitted by vehicle 14 to gather around one or moreof collector openings 36 may be impermeable (or substantially so) forone or both of exhaust emitted by vehicle 14 and/or water. In suchimplementations, gathering structure 20 may protect collector openings36 from precipitation. This may facilitate analysis of exhaust receivedby collector openings, as the introduction of ambient water fromprecipitation into exhaust may complicate one or both of transport ofthe exhaust by collector 18 and/or analysis of the collected exhaust.

In some instances, gathering structure 20 may include a roof. The roofmay be positioned over some or all of roadway 16. The roof may providethe one or more of the surfaces that gather exhaust emitted by vehicle14 around collector openings 36. The roof may be an “A-frame” roof, withcollector 18 running along at or near the interface between the twoplanes that form the “A-frame” roof (or the “peak” of the roof). Theroof may be supported a plurality of trusses (not shown). The trussesmay run substantially perpendicular to the general direction ofgathering structure 20. The roof may be supported above roadway 16 byone or more load-bearing supports 38. Supports 38 may include one ormore vertical structures with spaces in between.

In some implementations, gathering structure 20 may further comprise oneor more solid vertical planes (e.g., walls) that extend parallel to adirection of travel on roadway 16. The height of the walls may vary suchthat the walls may extend from the roof all the way down to the groundsurface, or partially down to the ground surface. Additionally, thelength of the walls may vary such that the walls may extend the entirelength of gathering structure 20, or only along a portion of the lengthof gathering structure 20. The solid vertical planes (or walls) may berigid, or may alternatively be formed of flexible, plastic material(e.g., such as flexible, plastic sheets (or aprons)). If the walls arerigid and load-bearing, then supports 38 may not be necessary. Bycontrast, if the walls are formed of flexible, plastic sheets (oraprons), the one or more load-bearing supports 38 (or other types ofsupports for the roof of gathering structure 20) may be provided.

In some implementations, either or both of the flexible, plastic sheets(or aprons) comprising the walls of gathering structure 20 may betransparent so as to not adversely impact the visibility of the driverof vehicle 14. For example, if roadway 16 comprises a separate test lane(or lanes) to which vehicle 14 has detoured from its route in order tohave its emissions tested separate from other traffic, the use oftransparent plastic sheets (or aprons) may be beneficial in that thedriver of vehicle 14 will be able to better see/monitor trafficconditions when, for example, departing gathering structure 20 andmerging back into traffic.

In various implementations, walls (as described above) may be providedon either or both sides of gathering structure (20). In some instances,no walls may be provided and the roof of gathering structure may, asdescribed above, be supported above roadway 16 by one or moreload-bearing supports 38 comprising vertical structures (e.g., posts,columns, etc.) with spaces in between. Configuring gathering structure20 to include one, two, or no walls extending parallel to a direction oftravel on roadway 16 may depend on a variety of factors including, forexample, the types of vehicles being tested. For example, if commercialand/or heavy-duty vehicles are being tested that have exhaust “stacks”that emit exhaust in an upward (vertical) direction, it may not benecessary to include walls as the roof of gathering structure 20 maydirect exhaust emissions to (or pool exhaust emissions near) one or moreopenings 36 of collector 18. Some “high-stack” vehicles, however, haveexhaust stacks that direct emissions outward (laterally) away from thevehicle at an elevated position. One example includes smaller rockhauler trucks that have exhaust stacks that are positioned lower andthat aim sideways to the right. Having a wall on the same side ofgathering structure 20 as the side of vehicle 14 where exhaust gases areemitted would help contain vehicle exhaust emissions within gatheringstructure 20 and/or guide such emissions toward one or more openings 36of collector 18.

The configuration of roadway 16 may also factor into a determination asto whether walls may be provided on either or both sides of gatheringstructure 20. For example, if roadway 16 comprises a separate test lane(or lanes) to which vehicle 14 has detoured from its route in order tohave its emissions tested separate from other traffic, gatheringstructure 20 may not include a wall on its left side, particularly ifvehicle 14 emits exhaust to the right-hand side and has to merge backinto traffic on its left-hand side (so as to improve visibility for thedriver). Alternatively, gathering structure 20 may not include a wall onits right side, particularly if vehicle 14 emits exhaust to theleft-hand side and has to merge back into traffic on its right-hand side(so as to improve visibility for the driver). In the exemplary andnon-limiting illustration of FIGS. 1-2, gathering structure 20 isdepicted with only one side wall 45 (on the right-hand side) extendingparallel to a direction of travel on roadway 16.

If a variety of high-stack emitters will likely be encountered during atesting session, including those that emit exhaust emissions eithervertically, to the left-hand side, and/or to the right-hand side suchthat it is desirable to have walls on both sides of gathering structure20, then, as noted above, gathering structure 20 may comprise two wallscomprising flexible, plastic sheets (or aprons) that are transparent soas to not adversely impact the visibility of the driver of vehicle 14.Alternatively, if roadway 16 comprises a separate test lane (or lanes)of sufficient length such that vehicle 14 has an ample distance to mergeback into traffic after departing gathering structure 20, either or bothof the walls of gathering structure 20 may be rigid, or plastic (but notnecessarily transparent). Many different configurations may beimplemented.

In some implementations of the invention, collector 18 receives air fromone or more collector locations above the surface of roadway 16.Collector 18 may be held in place at or near gathering structure 20 byone or more of a variety of different techniques for securing collector18 in place. These techniques may include, for example, fasteningcollector 18 to gathering structure 20 with an adhesive and/or one orfasteners (e.g., one or more U-bolts), and/or other techniques.Collector 18 may include one or more conduits with one or more collectoropenings 36 formed therein. For example, collector 18 may be formed fromone or more perforated pipes. Air can be drawn into collector 18 fromambient atmosphere via collector openings 36. Each of the collectoropenings 36 may form one of the aforementioned collector locations.

The position of collector openings 36 with respect to roadway 16 mayfacilitate reception by collector openings 36 of exhaust from vehicle 14where vehicle 14 is a commercial or heavy-duty vehicle. For example,collector 18 is illustrated in FIG. 1 and discussed herein as providingcollector openings 36 over roadway 16 to receive exhaust emitted at anelevated location and/or with an upward velocity by vehicle 14 (e.g.,from the “stacks” on a semi-tractor, etc.). This is not intended to belimiting. For example, in some implementations, collector 18 may providecollector openings along side roadway 16 above the surface of roadway 16(e.g., to collect exhaust emitted by vehicles that project exhaust outto the side). In certain implementations, collector 18 may include asingle conduit along which collector openings 36 are formed (as shown inFIG. 1). In certain implementations, collector 18 may include aplurality of separate conduits and/or conduit branches, with each of theconduits and/or conduit branches forming one or more of collectoropenings 36.

In some implementations of the invention, collector openings 36 may bedisposed between a first location and a second location on the roadway.The path between the first location and the second location maycorrespond to the path of vehicle 14 as it travels along roadway 16(e.g., the path defined for vehicle 14 by roadway 16). For example, asmay be seen in FIG. 1, in some implementations, collector openings 36may be disposed above the path of vehicle 14 along the roadway toreceive exhaust emitted by vehicle 14.

In some implementations of the invention, one or both of collector 18and/or gathering structure 20 may be portable between sites. Forexample, collector 18 may be removable from gathering structure 20 toenable collector 18 to be selectively implemented at a plurality ofdifferent sites that have gathering structures. As another example,gathering structure 20 may include a tent-like structure, or some otherportable structure that enables gathering structure 20 to be transportedwith collector 18 between sites.

Flow generator 22 may be in communication with collector 18, and may beconfigured to generate a flow of air within collector 18 that drawsambient air present at the collector locations into collector openings36, and through the conduit(s) formed by collector 18. As such, flowgenerator 22 may generate a negative pressure at an end of theconduit(s) of collector 18 opposite collector openings 36 to createsuction that draws the ambient air into collector openings 36. Flowgenerator 22 may include a vacuum pump, an impeller (or turbine), and/orother flow generators capable of generating a flow of air from collectoropenings 36 down into the conduit(s) of collector 18.

In some implementations, flow generator 22 may be configured tocontinuously draw air into collector 18 at a predetermined flow rate(e.g., 5.0 standard liters per minute) from collector openings 36. Asvehicle 14 passes by collector 18, a plug (or plugs) of air including asample of exhaust plume 16 may be drawn through collector openings 36and into the conduit(s) formed by collector 18. The air received thuslymay be delivered from collector 18 to component detection system 24(with which the conduit(s) of collector 18 is in fluid communication)for analysis, as is discussed below. The plug(s) of air including theexhaust sample remains essentially intact with minimal spreading as ittravels through collector 18. The length of the conduit(s) betweencollector openings 36 and component detection system 24 may differ invarious configurations as the distance between roadway 16 and componentdetection system 24, the height of collector openings 36 from thesurface of roadway 16, and/or other system parameters vary.

At collector openings 36, air may be substantially at atmosphericpressure. As was mentioned above, to induce a flow of air withincollector 18 that draws air into collector openings 36, flow generator22 may generate a reduced pressure within collector 18 that falls to apredetermined pressure level at or near a measurement cell 40 associatedwith component detection system 24, at which the presence of one or morecomponents in the air received from collector openings 36 may bequantified. In some instances, for example, the pressure in measurementcell 40 may decrease to approximately 50 torr. In one implementation,and as illustrated in FIG. 1, for example, flow generator 22 may belocated downstream of the measurement instruments comprising componentdetection system 24. In such a configuration, detectors (of componentdetection system 24) may be sampling under slight vacuum conditions.Alternatively, flow generator 22 may be located upstream of themeasurement instruments comprising component detection system 24 (notillustrated). In this instance, detectors (of component detection system24) may be sampling under atmospheric pressure, however, the blades ofthe turbine of flow generator 22 may disrupt some particles.

In various implementations, and as described in greater detail belowwith reference to FIG. 2, characteristics of collector 18 (e.g.,arrangement of openings, length, diameter, cross-section, etc.), and/oroperating parameters of flow generator 22 may be adjusted as necessaryto achieve desired flow rates and pressure drops within collector 18.Such adjustments to these and other components of system 10 may ensurethat optimal conditions exist for quantifying the presence of one ormore components in exhaust plume 14. Optimal conditions may varydepending on which components are being analyzed (e.g., which gaseouscomponents, what size particulate matter, etc.), as well as what type ofcomponent detection system 24 is being implemented to best quantify thepresence of the components of interest.

According to an implementation of the invention, component detectionsystem 24 may comprise any system capable of quantifying the presence ofone or more components in a sample of exhaust introduced into ameasurement space or cell 40 (via collector 18 and flow generator 22).As such, component detection system 24 may comprise a detector capableof determining concentrations of one or more gaseous constituentspresent in an exhaust sample, a detector capable of measuring thedensity of particulate matter present in an exhaust sample (e.g.,opacity, smoke, etc.), and/or other detectors. For example, componentdetection system 24 may comprise a mass spectrometer,visible/ultraviolet absorption spectrometer, infrared absorptionspectrometer, or other known or subsequently developed trace gasdetection instrument or system. Similarly, component detection system 24may comprise an aerosol mass spectrometer, condensation particlecounter, light scattering detector, laser incandescent particledetector, electrostatic particle charging detector, or other known orsubsequently developed fast response, fine particle instrument orsystem.

Similar to most (if not all) non-contact, remote emissions sensing (or“cross-road”) systems, including (but not limited to) those systemsdescribed in the U.S. Patents identified (and incorporated herein byreference) above, component detection system 24 may, in oneimplementation, be configured to determine the ratio of individualpollutants (e.g., CO, HC, NO, etc.) to CO₂ or to total carbon in a knownmanner to determine the concentration of the individual pollutants in anexhaust gas sample. The individual concentrations of pollutants indiluted exhaust may not in themselves be useful until assembled intoratios versus CO₂ from which can be determined emissions per kg of fuel,per gallon of fuel and, to a good approximation, to emissions per brakehorsepower hour (the units of the current government standard for newengine certification) to the extent that fuel consumption per brakehorsepower hour is reasonably well known for heavy duty diesel engines.Because ratios are used, it may not matter, for example, if one of theextractive measurement instruments (of component detection system 24) isslower in response than the others, or has a greater lag time beforereporting concentrations versus time. This may arise because, for eachinstrument, there may be a few seconds when an exhaust plume is known tobe present (e.g., from the CO₂ data with some extra time added on eachside) and the pollutant readings in the other instruments will beintegrated during that time frame, and then the integrals ratioed to theobserved CO₂ integral. In an illustrative (and non-limiting) example, aCO₂ detector may have a slower response time than a CO detector, andvehicle exhaust being measured may include both CO and CO₂ (above“background” levels). Further, in the example, a two-second, long plumeof well-mixed exhaust arrives at the detector manifold (of componentdetection system 24). The CO detector (having a faster response time)correctly measures a two-second long peak which is measured andintegrated above the background reading, while the slower CO₂ detectormay measure a four-second peak before it returns to the backgroundreading. However, each peak may be integrated regardless of the exacttime when the measurement was recorded, and the ratio of the twointegrals may be used as the average exhaust CO/CO₂ ratio from whichemissions per kg of fuel, per gallon of fuel, etc. are calculated.

In one implementation, background exhaust gas concentrations may, as inother remote sensing applications, be determined from the instrumentreadings (of component detection system 24) before and/or after anobserved CO₂ plume from vehicle 14 passing through gathering structure20 is recorded.

Further, calibration of component detection system 24 may be provided byinserting a puff of suitable synthetic exhaust gas with known RATIOsinto one or more of collector openings 36 or a separate calibration gasentrance (not illustrated) upstream of component detection system 24 toguarantee adequate mixing. Calibration of smoke parameters may beachieved using known calibration procedures (e.g., the extractiveinstrument manufacturer's calibration procedures).

According to one aspect of the invention, computer 26 may be inoperative communication with and/or control one or more components ofcomponent detection system 24, flow generator 26, vehicle communicationsystem 28, position tracking system 30, vehicle identification system32, and/or other components. For example, computer 26 may control a dataacquisition (or sampling) session, as well as process and store datafrom component detection system 24. Computer 26 may comprise a personalcomputer, portable computer (e.g., laptop computer), processor, or otherdevice. In some implementations, computer 26 may comprise one or more ofone or more processors, a user interface, memory, one or more storagedevices, and/or other components, which are electrically coupled via abus. The memory may comprise random access memory (RAM), read onlymemory (ROM), or other memory. The memory may store computer-executableinstructions to be executed by the one or more processors, as well asdata which may be manipulated by the one or more processors. The one ormore storage devices may comprise floppy disks, hard disks, opticaldisks, tapes, or other storage devices for storing computer-executableinstructions and/or data. The user interface may comprise interfaces tovarious peripheral devices (e.g., keyboard, mouse, microphones, externalstorage devices, monitors, printers or other input and/or output devicesas would be appreciated by those having skill in the art) as well asother components as described herein.

According to one aspect of the invention, computer 26 may be connectedby wire or wirelessly to a network (e.g., Internet, Intranet, etc.) sothat emissions data or other information may be made accessible via aweb site or other application (or transmitted a predetermined interval)to vehicle owners or operators, regulatory bodies (e.g., Dept. of MotorVehicles), or to other entities.

In some implementations, component detection system 24 takes a pluralityof “samples” of exhaust emitted by vehicle 14 as vehicle 14 is adjacentto (or, e.g., driving through or under) gathering structure 20. This maycomprise quantifying the presence of one or more components (e.g.,gaseous constituents, particulate matter, etc.) in air collected bycollector 18 periodically at a sampling rate over a time period duringwhich exhaust emitted by vehicle 14 while operating adjacent togathering structure 20 is being analyzed. For example, this time periodmay include a time period during which exhaust emitted by vehicle 14while traveling from a first location 42 at or near a first end of (orentrance to) gathering structure 20 to a second location 44 at or nearan opposite (or second) end of (or exit from) gathering structure 20 isbeing analyzed by component detection system 24. In some instances,component detection system 24 (or some subsequent processor, such ascomputer 26) aggregates the samples taken during the time period todetermine an aggregate quantification of the presence of the one or morecomponents in the exhaust of vehicle 14. Even if the vehicle is beingoperated in some atypical fashion (e.g., changing gears) during the timeperiod, the aggregation of the quantification may suppress inaccuraciescaused by this momentary atypical operation, and may be morerepresentative of the emissions of vehicle 14 under normal drivingconditions that a conventional remote sensing measurement. For example,values determined for each of the samples may be averaged or otherwiseaggregated to determine the aggregate quantification of the presence ofthe one or more components in the exhaust of vehicle 14.

In some instances, readings of component detection system 24 may beimplemented as a “trigger” that causes an aggregation of measurements ofexhaust components present in the air within collector 18. For example,a rise in CO₂, and/or some other exhaust component, in the air withincollector 18 (as determined by component detection system 24) above somepredetermined threshold may trigger the an aggregation of samples takenby component detection system 24. The aggregation may continue until theCO₂ within the air in collector 18 falls below the predeterminedthreshold, for a predetermined time period after the initial trigger,for a predetermined time period after the level of CO₂ falls below thethreshold, and/or for some other amount of time.

As should be apparent from the configuration of collector 18 andgathering structure 20 with respect to roadway 16, system 10 isconfigured to detect the presence of components in the exhaust ofvehicle 14 during normal operation of vehicle 14. Generally, the amountand composition of exhaust emitted by a vehicle is somewhat a functionof the conditions under which the vehicle is operating. For example,exhaust emitted by vehicle 14 while cruising at freeway speeds on alevel grade would be expected to be different in quantity and/orcomposition from exhaust emitted by vehicle 14 while accelerating from astopped position.

As such, vehicle communication system 28 may be provided to communicatewith the driver of vehicle 14 the manner in which vehicle 14 should beoperated while it is traveling along the path of roadway 16 that isadjacent to collector openings 36 (e.g., underneath collector openings36 between first location 42 and second location 44). For example,vehicle communication system 28 may communicate instructions to thedriver of vehicle 14 dictating the manner in which vehicle 14 should beoperated. In one implementation, the instructions may include: (1) aninstruction to bring vehicle 14 to a stop, or some predetermined lowspeed, at first location 42 at one end of gathering structure 20; and(2) an instruction to accelerate from the stop (or low speed) whiletraveling along the roadway adjacent to gathering structure 20 towardsecond location 44. The instruction to accelerate may include apredetermined upper speed that vehicle 14 should reach before exitingthe section of roadway adjacent to gathering structure 20 (e.g., atsecond location 44), a rate of acceleration, and/or other instructionsthat specify how much vehicle 14 should accelerate. In oneimplementation, the instructions may include a speed at which vehicle 14should be driven for the entire time that it is on roadway 16 betweenfirst location 42 and second location 44. Other implementations, inwhich vehicle communication system 28 communicates other operatingconditions to the driver of vehicle 14 exist.

In order to communicate with the driver of vehicle 14, vehiclecommunication system 28 may include one or more displays, one or morespeakers, and/or other interfaces that communicate information to thedriver of vehicle 14. In some implementations, the one or more displaysmay include one or more dynamic, electronic displays (e.g., monitors,screens, projectors, lights, etc.) that can be controlled to provideinformation to the driver of vehicle 14. In some implementations, theone or more displays may include one or more static, fixed displays(e.g., signs, lettering/figures formed on roadway 16, lettering/figuresformed on gathering structure 20, etc.), and/or other displays.

Although vehicle communication system 28 may be positioned proximate togathering structure 20 and/or collector 18, in some implementations,vehicle communication system 28 may provide communication to the driverof vehicle 14 at some predetermined distance from gathering structure 20and/or collector 18. For example, at some predetermined distance fromgathering structure 20 and/or collector 18, vehicle communication system28 may communicate to the driver of vehicle 14 that a test zone at whichthe emissions of vehicle 14 will be tested is upcoming, and that vehicle14 should achieve and/or maintain some predetermined speed whileadjacent to gathering structure and/or collector 18.

In some implementations of the invention, position tracking system 30may track the position, speed, acceleration, jerk, etc. of vehicle 14 asit travels along roadway 16 between first location 42 and secondlocation 44. Position tracking system 30 may include one or more ofinfrared motion sensors, pressure sensors, radar, lidar, sonar, and/oror other sensors capable of detecting the presence, speed, acceleration,etc. of vehicle 14.

The information determined by position tracking system 30 may becommunicated to computer 26, and may be processed by computer 26 todetermine the compliance of vehicle 14 with the instructions provided byvehicle communication system 28. This may enable computer 26 to “flag”instances where vehicle 14 has not been operated in accordance with theoperating conditions dictated by vehicle communication system 28 (e.g.,as invalid, as being of questionable accuracy and/or precision, etc.).

In some instances, the information determined by position trackingsystem 30 may be implemented to determine when exhaust emitted byvehicle 14 is being analyzed by component detection system 24 (asopposed to ambient air). For example, as was mentioned above, there isgenerally a delay between the reception of exhaust at collector openings36 and introduction of the received exhaust into component detectionsystem 24 (e.g., within measurement cell 40). The detection of theposition of vehicle 14 along roadway 16, coupled with a known amount oftime associated with this delay may enable a determination (e.g., bycomputer 26) as to when the exhaust emitted by vehicle 14 and receivedat collector openings has reached component detection system 24.

In some implementations, information related to the position of vehicle14 by position tracking system 30 may be implemented to “trigger”operation of one or both of flow generator 22 and/or component detectionsystem 24. For example, a determination by position tracking system 30that vehicle 14 is at or approaching gathering structure 20 (e.g., at orapproaching first location 42) may trigger flow generator 22 to begin togenerate a flow of air from collector openings 36 to component detectionsystem 24. In such instances, flow generator 22 may begin to generate aflow by opening a valve (e.g., to communicate the conduit(s) associatedwith collector 18 with a reduced pressure chamber), initiating a pump(e.g., to begin suction), and/or otherwise generating a flow fromcollector openings 36 to component detection system 24. Similarly, flowgenerator may cease the generation of a flow from collector openings 36to component detection system upon a determination by position trackingsystem 30 that vehicle 14 is exiting, or has exited, gathering structure20.

Data regarding the identification of those vehicle 14 passing adjacentto gathering structure 20 to have its exhaust tested may be acquired byvehicle identification system 32 or other known identification device orsystem (not illustrated) in operative communication with computer 26(e.g., via a wireless or hard-wired connection). Vehicle identificationsystem 32 may comprise, for example, a film camera, video camera, ordigital camera. Other imaging devices may also be used. Preferably, theimaging unit associated with vehicle identification system 32 may recordan image of the identification tag (e.g., license plate) of vehicle 14.Tag information may be processed by computer 26 to provide additionalinformation about vehicle 24. For example, a Motor Vehicle Departmentdatabases may be accessed to retrieve owner information, driverinformation, license information, make, model type, model year, or otherinformation.

According to one implementation of the invention, an identification tagon vehicle 14 may be read by vehicle identification system 32 toidentify the vehicle, and computer 26 may associate particular sensedvehicle emission information with the identified vehicle. In someimplementations, an identification tag (defined as a license plateabove), may comprise a transponder located on or within vehicle 14(e.g., hung from a rear view mirror, placed on the dashboard, etc.), orthat is integral within the vehicle (e.g., part of a global positioningsystem (“GPS”), located within the engine of the vehicle, or placed ormounted elsewhere). The transponder may transmit information aboutvehicle 14, including make and model of vehicle 14, enginecharacteristics, fuel type, the owner of vehicle 14, or otherinformation which may be pertinent. Information transmitted by thetransponder may be received by vehicle identification system 32.According to an implementation of the invention, a transponder may beused in connection with other functions. By way of example, atransponder may also be used in connection with a toll pass, whereby adriver can electronically pay tolls via the transponder without stoppingthe vehicle.

An identification tag may also comprise a tag or decal that requires areader associated with vehicle identification system 32. By way ofexample, an identification tag may comprise a decal with identifyingmarks (e.g., bar codes, infrared markings, etc.) containing informationabout vehicle 14. The decal may be located outside vehicle 14, such ason a front or rear bumper, on the under-side of vehicle 14, or any otherlocation on vehicle 14 where the decal may be suitably read. A readermay observe the decal and thereby obtain information about vehicle 14.

Computer 26 may receive information about vehicle 14 from a readerand/or receiver associated with vehicle identification system. Vehicleinformation and information obtained by sensing vehicle emissions may bestored. Computer 26 may correlate vehicle information received from anidentification tag with the results from vehicle emissions sensing.Computer 26 may update a vehicle record to include results obtained byprocessing vehicle emission data, such as information regarding whethera vehicle has passed or failed predetermined emissions criteria. Othervehicle identification systems may be implemented.

FIG. 2 illustrates an exemplary (non-limiting) implementation of system10. As shown, collector 18 may include an extraction portion 18 a, adelivery portion 18 b, and/or other portions. Extraction portion 18 amay include the portion of collector 18 in which collector openings 36are formed, and may be configured to extract vehicle emissions that havebeen gathered (or directed) into openings 36 by gathering structure 20.Delivery portion 18 b may be configured to deliver vehicle emissions(that have been extracted by extraction portion 18 a) to componentdetection system 24.

The emission extraction subsystem formed by extraction portion 18 a,delivery portion 18 b, collector openings 36, and flow generator 22 maybe configured such that the time it takes vehicle emissions extracted ata given one of collector openings 36 to reach delivery portion 18 band/or component detection system 24 is a function of the location ofthe given collector opening 36 between first location 42 and secondlocation 44. In some implementations, vehicle emissions extractedthrough one or more collector openings 36 closer to first location 42take longer to reach delivery portion 18 b than vehicle emissionsextracted through one or more collector openings 36 closer to secondlocation 44. For convenience, the time it takes for a sample of vehicleexhaust emissions to travel from an entry point in extraction portion 18a (e.g., entry being via one or more collector openings 36) to componentdetection system 24 will be referred to herein as the “collection time”of the sample.

As vehicle 14 is traveling on roadway 16 (as shown in FIGS. 1-2) in adirection from first location 42 toward second location 44, exhaustemissions from vehicle 14 arrive at one or more collector openings 36near first location 42 before exhaust emissions from vehicle 14 arriveat one or more collector openings 36 near second location 44. As such,by configuring one or more of extraction portion 18 a, delivery portion18 b, collector openings 36, and/or flow generator 22 such that thecollection time of a (first) sample of vehicle emissions extracted atone or more collector openings 36 located near first location 42 islonger than the collection time of a (second) sample of vehicleemissions extracted at one or more collector openings 36 located nearsecond location 44, exhaust emissions emitted by vehicle 14 betweenfirst location 42 and second location 44 (along roadway 16) areaggregated and/or condensed for analysis by component detection system24.

In other words, a sample of exhaust emissions emitted by vehicle 14relatively close to first location 42 may be introduced into deliveryportion 18 b of collector 18 at substantially the same time as a sampleof exhaust emissions emitted later in time when vehicle 14 is relativelyclose to second location 44. This aggregation of vehicle emissionsresults in an integrated (or aggregated) exhaust plume (or sample) thatis larger and easier to measure, thereby enhancing the accuracy and/orprecision of the analysis performed by component detection system 24(e.g., the determination of the concentrations of the gaseous componentsin the integrated sample).

In one implementation, a delay in collection time along extractionportion 18 a of collector 18 may be manipulated and/or controlled tosubstantially match the travel time of vehicle 14 along roadway 16. Forexample, if instructions provided to an operator of vehicle 14 (e.g., byvehicle communication system 28) result in a trip between first location42 and second location 44 having some trip duration, one or more ofextraction portion 18 a, delivery portion 18 b, collector openings 36,and/or flow generator 22 may be configured such that a collection timefor a (first) sample of vehicle exhaust emissions collected through oneor more collector openings 36 at or near first location 42 is longerthan a collection time for a (second) sample of vehicle exhaustemissions collected through one or more collector openings 36 at or nearsecond location 44, with the difference in collection times for thefirst and second samples being substantially equal to the trip duration.This difference in collection times may be determined, for example,based on a predicted trip duration (e.g., the trip duration ifdirections conveyed via vehicle communication system 28 are followed).Such directions may include instructions to maintain a given speed,accelerate, and/or deccelerate. The difference in collection times mayalso be determined based on measurements of vehicle position and/orspeed (e.g., by position tracking system 30), and/or determined in otherways.

A difference in collection times may be created in one or more of avariety of ways. For example, by positioning the interface betweenextraction portion 18 a and delivery portion 18 b relatively close tosecond location 44 (e.g., at or near second location 44), a sample ofvehicle exhaust emissions entering extraction portion 18 a at or nearfirst location 42 will have to travel the full length of extractionportion 18 a to reach delivery portion 18 b, while a sample of vehicleexhaust emissions collected at or near second location 44 will have amuch shorter path within extraction portion 18 a before reachingdelivery portion 18 b.

As another example, the size and/or shape of collector openings 36 maybe varied over the length of extraction portion 18 a to increase ordecrease the rates at which exhaust emissions are collected intoextraction portion 18 a through individual collector openings 36. In oneimplementation, for example, the size (diameter) and/or shape ofcollector openings 36 at or near first location 42 may be larger thanthe size (diameter) and/or shape of collector openings 36 at or nearsecond location 42.

In one non-limiting example, the size and/or shape of one or more ofcollector openings 36 may be static or dynamic (e.g., formed bycontrollable valves having variable opening size and/or shape).

As yet another non-limiting example, the rate at which flow generator 22pulls exhaust gases through delivery portion 18 b may be adjusted toadjust the differences in collection times for vehicle emissionscollected closer to first location 42 and vehicle emissions collectedcloser to second location 44. Other mechanisms for controlling thecollection times may be used in conjunction with or separate from thoseset forth herein.

The illustration of collector 18 as including a single path asextraction portion 18 a and a single path as delivery portion 18 bshould not be viewed as limiting. In some implementations, collector 18may include a plurality of separate lumens or other structures operatingas extraction portions 18 a and/or a plurality of separate lumens orother structures operating as delivery portions 18 b. In someimplementations, the inclusion of a plurality of separate extractionportions 18 a and/or delivery portions 18 b may enhance the ability todynamically adjust collection times for vehicle exhaust emissionsgathered and/or collected (via collector 18) at different locationsbetween first location 42 and second location 44. This may facilitateactive adjustment of collection times to accommodate different tripdurations for vehicle 14 along roadway 16.

In view of the foregoing description, one exemplary and non-limitingexample is provided with reference to FIG. 2. Particularly, in theexample, extraction portion 18 a of collector 18 may be approximatelyfifty feet in length, and collector openings 36 near first location 42may be larger than the collector openings 36 near second location 44(near delivery portion 18 b). If vehicle 14 enters gathering structureat or near first location 42 and takes approximately eight seconds totravel through gathering structure 20 before arriving at second location44, then a second sample of vehicle emissions extracted at a collectoropening 36 located near second location 44 will be entering thecollector opening 36 at approximately the same time as a first sample ofvehicle emissions previously extracted near first location 42 arrivesinside extraction portion 18 a (just inside the same collector opening36 near second location 44). This configuration assumes that flowgenerator 22 is configured to draw the first sample of vehicle emissions(extracted near first location 42) through the fifty-foot extractionportion 18 a in approximately eight seconds. As a result, when eightseconds worth of exhaust samples from vehicle 14 arrive at secondlocation 44 (near delivery portion 18 b), they are integrated into asample of dilute exhaust (i.e., the second sample of vehicle emissionsextracted at a collector opening 36 located near second location 44)with a much shorter time profile than the eight seconds spentcontributing to the air flow. This integration (in which eight secondsof exhaust samples is placed into about two seconds worth of air)compliments the integration to be performed by the suite of instrumentscomprising component detection system 24.

The location of delivery portion 18 b may be altered to change thedilution of exhaust from vehicle 14 so as to achieve readings mostsuitable for the suite of instruments comprising component detectionsystem 24, and to ensure adequate exhaust dilution to avoid watercondensation, inappropriate particle formation, or other occurrencesthat may negatively affect testing accuracy. Maximum dilution may, forexample, be achieved when delivery portion 18 b is located substantiallynear the entrance of gathering structure 20 near first location 42. Bycontrast, minimum dilution may, for example, be achieved when deliveryportion 18 b is located substantially near the exit of gatheringstructure 20 near second location 44 (as shown in FIG. 2). In variousimplementations, delivery portion 18 b may be located at any point alonggathering structure 20 between first location 42 and second location 44depending on testing goals and requirements.

According to an aspect of the invention, if the suite of instruments(comprising component detection system 24) used to monitor vehicleexhaust emissions is too sensitive for a particular testing application,or if the dilution of the vehicle exhaust emissions is too small toensure that water vapor is not condensed, or that excess particles arenot formed, or if other difficulties are encountered; a number ofmodifications may be implemented. For example, the extraction air flow(generated by flow generator 22) may be increased with a larger turbineand, if it is desirable to maintain the same linear flow rates, a largerdiameter collector 18 (or extraction tube) may be used, and/or theposition of delivery portion 18 b may be moved closer to the upstreamend of gathering structure 20 (e.g., closer to first location 42). Inthis configuration, with the same vehicle (and with reference to thenon-limiting example discussed above), an exhaust plume which mighthave, for example, occupied two seconds previously may now occupysixteen seconds because a first exhaust sample (at first location 42)arrives more or less immediately at component detection system 24, whilethe last exhaust sample (emitted at or near second location 44) occursapproximately eight seconds later and takes approximately eight moreseconds to travel back down extraction portion 18 a to delivery portion18 b and ultimately to component detection system 24.

FIG. 3 illustrates a method 46 of quantifying the presence of one ormore components in an exhaust plume of a vehicle traveling on a roadway,in accordance with one or more implementations of the invention.Although some of the operations of method 46 are discussed below withrespect to the components of system 10 described above and illustratedin FIGS. 1-2, it should be appreciated that this is for illustrativepurposes only, and that method 46 may be implemented with alternativecomponents and/or systems without departing from the scope of thisdisclosure. Further, the particular arrangement of the operationsillustrated in FIG. 3 and described hereafter is not intended to belimiting. In some implementations, various ones of the operations couldbe performed in an order other than the one set forth, various ones ofthe operations may be combined with others and/or be omitted altogether,and/or various additional operations may be added without departing fromthe scope of the disclosure, as should be appreciated.

At an operation 48, one or more openings of a collector and/or agathering structure may be positioned above the surface of the roadwaysuch that one or more surfaces of the gathering structure may causeexhaust emitted by the vehicle as it travels on the roadway to gatheraround the one or more openings of the collector. In someimplementations, the collector and/or the gathering structure may besimilar to or the same as collector 18 and/or gathering structure 20,shown in FIGS. 1-2 and described above.

At an operation 50, information related to the position of the vehicleis determined. The information related to the position of the vehiclemay include one or more of the position, speed, acceleration, and/orjerk of the vehicle. The information determined at operation 50 mayinclude one or both of information related to the position of thevehicle with respect to the gathering structure and/or collectoropenings positioned at operation 48, and/or the operating conditionsunder which the vehicle is operating while it is adjacent to thegathering structure and/or collector openings. In some implementations,operation 50 may be performed by a position tracking system that is thesame as or similar to position tracking system 30, shown in FIGS. 1-2and described above.

At an operation 52, exhaust emitted by the vehicle may be received intothe plurality of collector openings. Receiving the exhaust into theplurality of collector openings may include generating a flow of airfrom the collector openings into the collector that draws the exhaustinto the collector by way of the collector openings. The flow of air maybe created via suction within the collector. In some instances, thegeneration of the flow of air may be triggered by a determination of theposition of the vehicle at operation 50 (e.g., that the vehicle is at orapproaching the gathering structure and/or collector openings). In someimplementations, the flow of air may be generated by a flow generatorthat is the same as or similar to flow generator 22, shown in FIGS. 1-2and described above.

At an operation 54, exhaust received into the collector openings atoperation 52 may be analyzed to quantify the presence of one or morecomponents in the received exhaust. The exhaust may be delivered fromthe collector openings to a component detection system by the flow ofair generated at operation 52, and the component detection system mayperform the analysis of the received exhaust at operation 54. In someinstances, the analysis of the presence of components in air received atoperation 52 into the collector openings may be triggered by adetermination of the position of the vehicle at operation 50 (e.g., thatthe vehicle is at or approaching the gathering structure and/orcollector openings). In some implementations, the component detectionsystem may include a component detection system that is the same as orsimilar to component detection system 24, shown in FIGS. 1-2 anddescribed above.

At an operation 56, instructions may be provided to the vehicle thatdictate the manner in which the vehicle should be operated when it isadjacent to the gathering structure and/or collector openings positionedat operation 48. In some instances, the instructions may be dynamic(e.g., delivered via an electronic display and/or speaker. In someinstances, the instructions may be static (e.g., delivered via signage).In some implementations, operation 56 may be performed by a vehiclecommunication system that is the same as or similar to vehiclecommunication system 28, shown in FIGS. 1-2 and described above.

At an operation 58, compliance of the vehicle with the instructionsprovided to the vehicle at operation 56. The compliance of the vehiclewith the provided instructions may be based on information related tothe position, speed, acceleration, and/or jerk of the vehicle determinedat operation 50. In some implementations, operation 58 may be performedby a computer that is similar to or the same as computer 26, shown inFIGS. 1-2 and described above.

At an operation 60, the vehicle and/or vehicle information related tothe vehicle (e.g., owner information, driver information, licenseinformation, make, model type, model year, etc.) may be identified. Insome implementations, operation 60 may be performed by a vehicleidentification system that is the same as or similar to vehicleidentification system 32, shown in FIGS. 1-2 and described above.

At an operation 62, results of the analysis performed at operation 54may be correlated with one or both of compliance information determinedat operation 58 and/or vehicle information identified at operation 60.This may create a record that relates results of the analysis with theappropriate vehicle (and/or class of vehicle), and/or specifies at leastsome of the parameters under which testing was conducted (e.g., whetherthe vehicle complied with the instructions provided at operation 58during the testing).

FIG. 4 illustrates a method 64 of analyzing exhaust to quantify thepresence of one or more components in the exhaust, according to one ormore implementations of the invention. In the description of method 64and one or more of its operations below, specific reference is made tovarious components shown in FIGS. 1-2 and described above and/or variousoperations shown in FIG. 3 and described above. However, this should notbe viewed as limiting. Instead, method 64 should be appreciated as beingusable with a variety of different systems and methods. Further, theparticular arrangement of the operations of method 64 illustrated inFIG. 4 and described hereafter is not intended to be limiting. In someimplementations, various ones of the operations could be performed in anorder other than the one set forth (or concomitantly with other ones ofthe operations), various ones of the operations may be combined withothers and/or be omitted altogether, and/or various additionaloperations may be added without departing from the scope of thedisclosure, as should be appreciated.

At an operation 66, a determination may be made as to whether analysisof the exhaust should begin (or has begun). Operation 66 may includedetermining whether exhaust received into collector openings adjacent toa roadway along which a vehicle is traveling has reached a componentdetection system performing the analysis. For example, operation 66 mayinclude determining whether exhaust received at operation 52 of method46, shown in FIG. 3 and described above, has reached the componentdetection system. The determination made at operation 66 may be based ona position of the vehicle (e.g., at operation 50 of method 46) and/or aknown delay time between the reception of the exhaust into the collectoropenings and the arrival of the received exhaust at the componentdetection system. In some implementations, operation 66 may be performedby a computer that is the same as or similar to computer 26, shown inFIGS. 1-2 and described above.

If the determination is made at operation 66 that analysis of theexhaust should not (or has not) begun, method 64 performs operation 66yet again. If the determination is made at operation 66 that analysis ofthe exhaust should begin, then method 64 proceeds to an operation 68, atwhich the exhaust is sampled to quantify the presence of one or morecomponents. In some instances, this may include taking a singlemeasurement of the one or more components and proceeding to an operation70. In some instances, this may include taking a series of samples at apredetermined sampling interval and then proceeding to operation 70. Insome implementations, operation 68 may be performed by a componentdetection system that is the same as or similar to component detectionsystem 24, shown in FIGS. 1-2 and described above.

At operation 70, a determination may be made as to whether analysis ofthe exhaust should cease (or has ceased). Operation 70 may includedetermining whether exhaust received into collector openings adjacent toa roadway along which a vehicle is traveling is no longer reachingcomponent detection system performing the analysis (e.g., because thevehicle has passed the collector openings). For example, operation 70may include determining whether all of the exhaust received at operation52 of method 46, shown in FIG. 3 and described above, has already beensampled and exhausted by the component detection system. Thedetermination made at operation 70 may be based on a position of thevehicle (e.g., at operation 50 of method 46) and/or a known delay timebetween the reception of the exhaust into the collector openings and thearrival of the received exhaust at the component detection system. Insome implementations, operation 70 may be performed by a computer thatis the same as or similar to computer 26, shown in FIGS. 1-2 anddescribed above.

If the determination is made at operation 70 that analysis of theexhaust should not cease (or has not ceased), method 64 may return tooperation 68. If the determination is made at operation 70 that analysisof the exhaust should cease (or has ceased), then method 64 may proceedto an operation 72.

At operation 72, the samples quantifying the presence of the one or morecomponents in the exhaust, taken at operation 68, are aggregated by oneor more of several possible mathematical techniques to provide anaggregate quantification of the presence of the one or more componentsin the exhaust of the vehicle. In some instances, operation 72 mayinclude averaging the samples. In some implementations, operation 72 maybe performed by a computer that is the same as or similar to computer26, shown in FIGS. 1-2 and described above.

Although the invention has been described in detail for the purpose ofillustration based on what is currently considered to be the mostpractical and preferred implementations, it is to be understood thatsuch detail is solely for that purpose and that the invention is notlimited to the disclosed implementations, but, on the contrary, isintended to cover modifications and equivalent arrangements that arewithin the spirit and scope of the appended claims. For example, it isto be understood that the present invention contemplates that, to theextent possible, one or more features of any implementation can becombined with one or more features of any other implementation.

In one alternative implementation, and with reference to FIG. 5, system10 may further comprise a remote emissions sensing (“RES”) system thatmay be used in lieu of, or in addition to, the extractive samplingsystem described in detail above.

The RES system may be configured to measure emissions in exhaust plume12 (of vehicle 14) in an optical measurement path 500 that runs in adirection substantially parallel to extraction portion 18 a of collector18 (or, in other words, in a direction substantially parallel to adirection of travel of vehicle 14 on roadway 16). In this regard,exhaust emitted by vehicle 14 may be directed by gathering structure toan elevated position above roadway 16 such that the exhaust is presentin optical measurement path 500.

In one implementation, the RES system may comprise a source/detectorunit 510 positioned at or near first location 42 (e.g., at a first endor entrance to gathering structure 20). The source/detector unit 510 maybe provided at an elevated position above roadway 16 (e.g., hung fromthe roof of gathering structure 20).

Source/detector unit 510 may comprise one or more sources ofelectromagnetic radiation (ER) which may be used in the absorptionspectroscopy measurement of various components of vehicle exhaustemissions in a known manner. The source may comprise an infrared (IR)radiation source. In alternative implementations, other types ofradiation sources may be used including, for example, an ultraviolet(UV) source, a visible light source, or other suitable sources as knownand understood by those having skill in the art. In someimplementations, a combination of radiation sources may be used.

Source/detector unit 510 may further comprise one or more detectors or adetector array for detecting radiation in a known manner. A detectorarray may be chosen to permit detection of electromagnetic radiationemitted by the source. For example, the detector array may comprise aphotodetector (e.g., a photodiode), a photomultiplier tube (PMT), aspectrometer, or any other suitable radiation detector. In oneimplementation, a mercury cadmium telluride (Hg—Cd—Te) photodetector maybe used to detect IR radiation. Other suitable detectors or detectorarrays or combinations thereof may also be used. In one implementation,a single detector with multiple filters may be used instead of an arrayemploying multiple detectors. The multiple filters may be moveable, suchas spinning filters, to allow multiple components to be detected. Inthis regard, a single detector can be employed to detect a plurality ofdifferent exhaust components because each of the moveable filters isdesigned to allow only the wavelength band of interest by a particularexhaust component to pass to the detector. According to yet anotherimplementation, the RES system may comprise a spectrometer, or otherdetecting device which may be used to detect more than one component.

In one implementation, the RES system may comprise transfer optics 520mounted in a manner to allow radiation from the source ofsource/detector unit 510 to be reflected back to the detector array ofsource/detector unit 510 along measurement path 500 for analysis.Transfer optics 520 may be positioned at or near second location 44(e.g., at a second end or exit from gathering structure 20). Transferoptics 520 may be provided at an elevated position above roadway 16(e.g., hung from the roof of gathering structure 20) and aligned withsource/detector unit 510. Transfer optics 520 may comprise a mirror,flat mirror, lateral transfer mirror (LTM), vertical transfer mirror(VIM), retroflector, or other device. In one implementation, transferoptics 520 may comprise a lateral transfer mirror to reflect radiationfrom the source along a path displaced laterally or vertically,depending on orientation, from the incident direction. Otherconfigurations may be implemented.

In some implementations, the position of source/detector unit 510 andtransfer optics 520 may be reversed such that source/detector unit 510may be positioned at or near second location 44 (e.g., at a second endor exit from gathering structure 20), while transfer optics 520 may bepositioned at a first location 42 (e.g., at a first end or entrance togathering structure 20).

Additionally, in other implementations (not illustrated),source/detector unit 510 may be replaced with a unit that includes asource, while transfer optics 520 may be replaced with a unit thatincludes a detector (aligned with the source). In this implementation, abeam of radiation makes one pass along measurement path 500 (i.e., fromthe source to the detector) rather than two passes along measurementpath as shown in FIG. 5 (from source/detector unit 510 to transferoptics 520 and then back to source/detector unit 510). Of course, insome implementations, transfer optics 520 may be replaced with a unitthat includes a source, and source/detector unit 510 may be replacedwith a unit that includes a detector (aligned with the source). Otherconfigurations may be implemented.

According to an aspect of the invention, source/detector unit 510,transfer optics 520, and/or other components of the RES system may be inoperative communication with one or more of the other components ofsystem 10 (described in detail above) including, for example, computer26, vehicle communication system 28, position tracking system 30,vehicle identification system 32, and/or other components.

Computer 26 may execute one or more software applications to calculatethe relative amounts of various exhaust gas constituents, concentrationsof various exhaust gas constituents (e.g., HC, CO₂, NO_(x), CO, etc.),the decay rate (e.g., dissipation in time) of the exhaust constituents,the opacity of an exhaust plume, the temperature, speed and accelerationof the vehicle, and to determine other desirable information as well.

In one implementation, computer 26 may calculate the relative amounts ofvarious exhaust gas constituents by computing the ratio of theabsorption for a particular exhaust gas constituent to the CO₂ gasconstituent. For example, in one implementation, the source (ofsource/detector unit 510) may be configured to pass a beam of EMradiation through exhaust plume 12 (present in optical measurement path500) of vehicle 14 as vehicle 14 passes through gathering structure 20.The beam may be directed by transfer optics 520 back to the detector (ordetector array) of source/detector unit 510. One or more filters (notillustrated) may be associated with the detector array to the enabledetector array to determine the intensity of EM radiation having aparticular wavelength or range of wavelengths. The wavelengths may beselected to correspond to wavelengths absorbed by molecular species ofinterest in an exhaust plume (e.g., hydrocarbons (HC), carbon monoxide(CO), carbon dioxide (CO₂) and nitrogen oxides (NO_(x)) such as NO andNO₂). One or more detector output voltages represent the intensity ofthe EM radiation measured by that detector.

These voltages are then input to computer 26. Computer 26 may calculatethe difference between the known intensity of the source and theintensity detected by the detectors to determine the amount ofabsorption by the particular molecular species (based on predeterminedwavelengths associated with that species). Based on the measuredabsorption(s), the number of molecules in the measurement path of one ormore molecular species in the emissions may be determined in a knownmanner.

Calibration of the RES system may be enabled by a calibration cell (notillustrated), or through puff calibration (via a calibration gascanister), as known in the art.

As noted above, the RES system may be used independently, or in additionto the extractive sampling system (e.g., collector 18, gatheringstructure 20, flow generator 22, component detection system 24, etc.)described in detail above.

For example, in one implementation, gaseous pollutants in vehicleexhaust emissions may be monitored optically (via the RES system) whilevarious parameters of smoke, such as black carbon content or sizedistribution, may be monitored using the extractive sampling system. Ofcourse, in one implementation, smoke may be measured optically via theRES system as described in, for example, U.S. Pat. No. 6,701,056, whichis hereby incorporated herein by reference in its entirety.

In an alternative implementation, similar measurements may be made byboth the RES system and the extractive sampling system for datavalidation or comparison purposes.

Other implementations, uses and advantages of the invention will beapparent to those skilled in the art from consideration of thespecification and practice of the invention disclosed herein. Thespecification should be considered exemplary only, and the scope of theinvention is accordingly intended to be limited only by the followingclaims.

1. A system configured to be positioned at a site along a roadway, andto determine the concentration of one or more constituents present in asample of exhaust emissions emitted by a vehicle traveling on theroadway from a first location on the roadway to a second location on theroadway, the system comprising: a component detection system configuredto determine the concentration of one or more constituents present invehicle exhaust emissions; a collector operatively coupled to thecomponent detection system, wherein the collector is positioned abovethe surface of the roadway and has one or more openings for receivingthe exhaust emissions of the vehicle to be analyzed by the componentdetection system; a gathering structure having one or more surfacespositioned to direct the exhaust emissions of the vehicle to be analyzedby the component detection system to the one or more openings of thecollector prior to measurement by the component detection system;wherein the component detection system is configured to receive a sampleof the exhaust emissions of the vehicle via the collector, and todetermine the concentration of one or more constituents present in thesample of exhaust emissions; and wherein the collector is configuredsuch that collection times for exhaust emissions emitted by the vehicleto be conveyed through the collector to the component detection systemvary as a function of position of the one or more openings of thecollector along the roadway between the first location and the secondlocation to aggregate the exhaust emissions for detection within thecomponent detection system.
 2. The system of claim 1, wherein theroadway comprises a test lane.
 3. The system of claim 1, wherein thegathering structure comprises a roof that is supported above the surfaceof the roadway by one or more supports such that the vehicle can passunder the roof while traveling along the roadway.
 4. The system of claim1, wherein the roadway comprises a single vehicle travel lane, andwherein the roof of the gathering structure covers the single vehicletravel lane.
 5. The system of claim 1, wherein the collector comprises:an extraction portion which runs parallel to a direction of travel ofthe roadway, with the one or more openings being formed therein; and adelivery portion configured to convey exhaust emissions extracted by theextraction portion through the one or more openings toward the componentdetection system, wherein the location at which the delivery portioninterfaces with the extraction portion facilitates aggregation of theexhaust emissions at the interface.
 6. The system of claim 5, whereinthe extraction portion interfaces with the delivery portion at or nearan end of the extraction portion that is located nearest the secondlocation.
 7. The system of claim 5, wherein the extraction portioncomprises a perforated lumen.
 8. The system of claim 7, wherein one ormore of a size, shape, or distribution of the perforations permit freerflow into the extraction portion of the collector for locations that arecloser to the first location.
 9. The system of claim 1, wherein thecollector is fastened to an underside of the roof of the gatheringstructure such that the one or more openings of the collector face thesurface of the roadway.
 10. The system of claim 1, wherein the gatheringstructure further comprises: a roof that is supported above the surfaceof the roadway by one or more supports such that the vehicle can passunder the roof while traveling along the roadway; and an apron thatextends from the roof toward the surface of the roadway on a first sideof the roadway, and further extends parallel to a direction of travel onthe roadway, wherein the apron is configured to direct exhaustemissions, emitted by a vehicle outward in a direction toward the firstside of the roadway, toward the one or more openings of the collector.11. A method of determining the concentration of one or moreconstituents present in a sample of exhaust emissions emitted by avehicle traveling on a roadway from a first location to a secondlocation, the method comprising: directing the exhaust emissions of thevehicle to be analyzed by a component detection system to one or moreopenings of a collector, prior to measurement by the component detectionsystem, via one or more surfaces of a gathering structure, wherein thecollector is positioned above the surface of the roadway; drawingexhaust emissions received in the one or more openings of the collectorto the component detection system via suction, wherein the collector isconfigured such that collection times for exhaust emissions drawnthrough the one or more openings of the collector to the componentdetection system vary as a function of position of the one or moreopenings of the collector along the roadway between the first locationand the second location to aggregate the exhaust emissions for detectionwithin the component detection system.
 12. The method of claim 11,wherein the roadway comprises a test lane.
 13. The method of claim 11,wherein the gathering structure comprises a roof that is supported abovethe surface of the roadway by one or more supports such that the vehiclecan pass under the roof while traveling along the roadway.
 14. Thesystem of claim 11, wherein the roadway comprises a single vehicletravel lane, and wherein the roof of the gathering structure covers thesingle vehicle travel lane.
 15. The method of claim 11, wherein thecollector comprises: an extraction portion which runs parallel to adirection of travel of the roadway, with the one or more openings beingformed therein; and a delivery portion configured to convey exhaustemissions extracted by the extraction portion through the one or moreopenings toward the component detection system, wherein the location atwhich the delivery portion interfaces with the extraction portionfacilitates aggregation of the exhaust emissions at the interface. 16.The method of claim 15, wherein the extraction portion interfaces withthe delivery portion at or near an end of the extraction portion that islocated nearest the second location.
 17. The method of claim 15, whereinthe extraction portion comprises a perforated lumen.
 18. The method ofclaim 17, wherein one or more of a size, shape, and/or distribution ofthe perforations permit freer flow into the extraction portion forlocations that are closer to the first location.
 19. The method of claim11, wherein the collector is fastened to an underside of the roof of thegathering structure such that the one or more openings of the collectorface the surface of the roadway.
 20. The method of claim 11, wherein thegathering structure further comprises a roof that is supported above thesurface of the roadway by one or more supports such that the vehicle canpass under the roof while traveling along the roadway; and an apron thatextends from the roof toward the surface of the roadway on a first sideof the roadway, and further extends parallel to a direction of travel onthe roadway, wherein the apron is configured to direct exhaustemissions, emitted by a vehicle outward in a direction toward the firstside of the roadway, toward the one or more openings of the collector.21. A system configured to be positioned at a site along a roadway, andto determine the concentration of one or more constituents present in asample of exhaust emissions emitted by a vehicle traveling on theroadway, the system comprising: a gathering structure having a firstend, a second end, and a roof having a length that extends from thefirst end of the gathering structure to the second of the gatheringstructure in a direction substantially parallel to a direction of travelof the roadway, wherein the roof of the gathering structure is supportedabove the surface of the roadway by one or more supports and poolsexhaust emissions emitted by the vehicle as the vehicle passes under theroof while traveling on the roadway; at least one radiation sourcedisposed on a underside of the roof of the gathering structure proximateto the first end of the gathering structure, the radiation sourceconfigured to emit a radiation beam along an optical measurement path,wherein the optical measurement path extends in a directionsubstantially parallel to a direction of travel of the roadway and alongan underside of the roof so as to pass through the exhaust emissions ofthe vehicle pooled by the gathering structure; at least one radiationdetector configured to receive the radiation beam and generate at leastone signal indicative of the radiation absorption of first and secondvehicle exhaust constituents in first and second wavelength bands; and acomputer configured to receive the at least one signal and calculate aratio of the radiation absorption of the first vehicle exhaustconstituent to the radiation absorption of the second vehicle exhaustconstituent.
 22. The system of claim 21, wherein the at least oneradiation detector is disposed on a underside of the roof of thegathering structure proximate to the second end of the gatheringstructure such that the radiation beam makes a single pass along theoptical measurement path from the at least one radiation source, throughthe exhaust emissions of the vehicle pooled by the gathering structure,to the at least one radiation detector.
 23. The system of claim 21,wherein the at least one radiation detector is disposed on a undersideof the roof of the gathering structure proximate to the first end of thegathering structure and adjacent to the at least one radiation source,the system further comprising: optics disposed on a underside of theroof of the gathering structure proximate to the second end of thegathering structure, the optics configured to reflect the radiation beamemitted by the at least one radiation source back along the opticalmeasurement path to the at least one radiation detector such that theradiation beam makes at least two passes through the exhaust emissionsof the vehicle pooled by the gathering structure.
 24. The system ofclaim 21, wherein the first vehicle exhaust constituent comprises one ofCO, HC, or NO.
 25. The system of claim 21, wherein the second vehicleexhaust constituent comprises carbon dioxide (CO₂).